Q: Which laboratories should consider implementing digital microscopy?

A: There are different digital microscopy systems for a variety of laboratory settings. Most, if not all of these systems have capabilities for remote review, which is almost universally beneficial because it enables technologists to perform complete blood counts with differentials even when they aren’t in the hematology area, near the slides, or at a microscope. Some laboratories might use this capability to flex staffing where it is most needed at a given time. Small or remote laboratories that might not have the appropriate laboratory professionals on-site can also use this feature to have their differentials performed remotely or to consult those with more expertise at other sites.

What are the benefits of digital microscopy?

Most digital microscopy systems have onboard libraries of images of different types of cells. Labs can use these during training, and technologists can also refer to them when performing a differential. This and the fact that technologists can easily review a patient’s previous cells on a digital system help to increase standardization and quality.

Many technologists also prefer the ergonomic experience with digital microscopy. Because it involves viewing images on a screen rather than at a microscope, they can sit back comfortably in a chair with less neck and wrist strain.

Automated digital microscopy systems add efficiency in larger and specialized laboratories. For example, in our laboratory a slide can be made on a slide-maker/stainer and imaged by the digital microscope without any human intervention. Another potential way to improve efficiency with this technology is to implement slide scans; if a sample is flagged for potential abnormal cells, the technologist can quickly scroll through to verify abnormal cells are absent and release the automated result without having to spend time classifying each cell type.

However, data conflict about whether or not digital microscopy systems actually lessen the time required to perform a differential. These systems provide an obvious benefit for samples with low leukocyte counts since they find and image the cells before a technologist looks at a case, saving the time required to “hunt” for cells. Some instruments even merge images from two slides to get adequate cells for a differential. Interestingly, in our lab the technologists who speed up the most when using digital microscopy are those with fewer years of experience.

What are the barriers to implementing a digital microscopy system?

As with any analyzer, labs must perform a validation study first before putting these systems in place. A more significant challenge is that some staff might resist the change if they are not that comfortable using computers and software. Some technologists also just prefer the experience of looking at a glass slide. While digital microscopy images are generally high quality, you must have adequate computer monitors to approximate the resolution that manual microscopy provides. Different light sources also affect digital image quality. With time, users do become more accustomed to using digital systems and reviewing the images, but some will always prefer the manual option.

What are some limitations of current digital microscopy systems?

One major limitation is that the system may only scan a set area of a slide. In these cases, a technologist has to manually review the slide to look at the feathered edge for suspected platelet clumps (pseudothrombocytopenia). Additionally, larger cells that tend to spread to the edges of the smear may be missed when this happens.

Another potential drawback right now is that a single vendor dominates the market. So many of the things I have mentioned may change as that company’s systems evolve or other companies develop new systems. As things currently stand, though, digital microscopy cannot entirely replace its manual counterpart. 

Dr. Nakashima will discuss this topic during two roundtable talks (session numbers 43110 and 53210) at the 2020 AACC Annual Scientific Meeting on December 15 at McCormick Place, Chicago.

Megan O. Nakashima, MD, is medical director for automated hematology and urinalysis and a staff hematopathologist at Cleveland Clinic in Ohio. +Email: nakashm@ccf.org